@book{211,
	author = {Cox,James M.},
	title = {Low back pain :},
	publisher = {Williams & Wilkins,},
	year = {1999.},
	address = { Baltimore:},
	edition = {6th ed.},
	note = {Includes bibliographical references and index. },
	url = {https://www.amazon.com/Low-Back-Pain-Mechanism-Diagnosis/dp/0683303589}
}